Reclusive North Korea, which has made no secret of its pursuit of a nuclear-tipped missile capable of reaching the mainland US, is also concerned about joint US-South Korea military exercises, which it sees as preparation for war.

South Korean officials have said the drills will start next month as planned.

The 10-member South Korean delegation, led by National Security Office head Chung Eui-yong, was greeted by North Korean officials after landing in Pyongyang on Monday, said Kim Eui-kyeom, a spokesman for South Korea's presidential office.

The North Koreans at the airport included Ri Son Gwon, chairman of the Committee for the Peaceful Reunification of the Country, and Kim Yong Chol, who heads the United Front Department, the North Korean office responsible for handling inter-Korean affairs. Both visited South Korea during the Winter Olympics last month.

The South Korean delegation was later invited to join Kim Jong-un for dinner, the South Korean spokesman added.

The South Korean officials are the most senior officials from the South to meet Kim Jong-un since he took power in late 2011 following the death of his father, Kim Jong Il.

"We will deliver President Moon Jae-in's wish to bring about denuclearisation of the Korean peninsula and permanent peace by extending the goodwill and better inter-Korean relations created by the Pyeongchang Winter Olympics," Mr Eui-yong said in South Korea before the delegation's departure.

Mr Eui-yong is due to fly to Washington later in the week to brief US officials on their discussions in the North.

Thawing relations between the Korean neighbours have prompted speculation about direct talks between Washington and Pyongyang after months of tension and exchanges of bellicose insults between US President Donald Trump and Kim Jong-un fuelled fears of war.